Backend:
- Add XP, level, streak fields to User model
- Add tier, category, xp_reward fields to Badge model
- Create gamification service with XP, levels, streaks, badge checking
- Add gamification router with level progress, leaderboard endpoints
- Define 16 badge types across attendance, ratings, social, milestones
Frontend:
- LevelProgressCard component with XP bar and streak display
- XPLeaderboard component showing top users
- Integrate level progress into profile page
Slug System:
- All entities now support slug-based URLs
- Performances use songslug-YYYY-MM-DD format
